U.S. patent number 5,332,273 [Application Number 07/921,935] was granted by the patent office on 1994-07-26 for actuator for door lock mechanism.
This patent grant is currently assigned to Harada Kogyo Kabushiki Kaisha. Invention is credited to Hiroshi Komachi.
United States Patent |
5,332,273 |
Komachi |
July 26, 1994 |
Actuator for door lock mechanism
Abstract
An actuator for a door lock mechanism, that is capable of
sufficiently securing a strong driving force as well as a necessary
stroke quantum, that is small in size, and that makes manual
operation possible under a light load, comprising: a columnar body
that is rotated by a forward-reverse motor and provided with, on
its outer circumferential surface, a first spiral stage, which
forms an upward gradient in a first direction when the columnar
body rotates in a forward direction, a second spiral stage which
forms an upper-gradient in a second direction when the columnar
body rotates in a reverse direction; and a displacement component
having one end driven to move in the first direction by the first
spiral stage at the time of the positive rotation of the columnar
body and in the second direction by the second spiral stage when
the columnar body rotates in the reverse direction, thus causing
another end of the displacement component to actuate a latch
mechanism for locking doors.
Inventors: |
Komachi; Hiroshi (Tokyo,
JP) |
Assignee: |
Harada Kogyo Kabushiki Kaisha
(Tokyo, JP)
|
Family
ID: |
25446217 |
Appl.
No.: |
07/921,935 |
Filed: |
July 29, 1992 |
Current U.S.
Class: |
292/336.3;
292/DIG.25 |
Current CPC
Class: |
E05B
81/25 (20130101); Y10S 292/25 (20130101); Y10T
292/57 (20150401) |
Current International
Class: |
E05B
65/12 (20060101); E05C 003/06 (); F16H
057/00 () |
Field of
Search: |
;292/201,336.3,DIG.25,144 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Moore; Richard E.
Attorney, Agent or Firm: Koda and Androlia
Claims
I claim:
1. An actuator for a door lock mechanism comprising:
a motor that rotates reciprocally in response to a control signal
supplied thereto;
a columnar body driven to rotate by said motor, said columnar body
having, on the peripheral surface, a first spiral stage, which
provides an upward gradient in a first direction along a center
axis of said columnar body when said columnar body rotates in a
forward direction, and a second spiral stage, which provides an
upward gradient in a second direction along said center axis of
said columnar body when said columnar body rotates in a reverse
direction; and
a displacement component, one end of said displacement component
being driven to move in said first direction by said first spiral
stage when said columnar body makes said forward rotation and also
being driven to move in said second direction by said second spiral
stage when said columnar body makes said reverse rotation, thus
causing another end of said displacement component to actuate a
door lock latch mechanism; and
wherein said columnar body is rotated to return to its original
position via a rebounding force of a spring after being driven to
rotate a specific angle by said motor, and said displacement
component, first spiral stage and second spiral stage are set for
their mutual positional relations so as to prevent said one end of
said displacement component from coming into contact with said
first and second spiral stages at least when said columnar body is
in said original position after rotating back thereto.
2. An actuator for a door lock mechanism comprising:
a motor that rotates reciprocally in response to a control signal
supplied thereto;
a columnar body driven to rotate by said motor, said columnar body
having, on the peripheral surface, a first spiral stage, which
provides and upward gradient in a first direction along a center
axis of said columnar body when said columnar body rotates in a
forward direction, and a second spiral stage, which provides an
upward gradient in a second direction along said center axis of
said columnar body when said columnar body rotates in a reverse
direction; and
a displacement component, one end of said displacement component
being driven to move in said first direction by said first spiral
stage when said columnar body makes said forward rotation and also
being driven to move in said second direction by said second spiral
stage when said columnar body makes said reverse rotation, thus
causing another end of said displacement component to actuate a
door lock latch mechanism; and
wherein said first spiral stage and said second spiral stage are
formed in such a manner that a lead angle of spiral portions of
said spiral stages is changed gradually relative to an outer
circumferential surface of said columnar body which is in a conical
shape.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an actuator for a door lock
mechanism used for, for example, an automobile.
2. Prior Art
In conventional door lock system actuators of this type, a motor
power is transmitted via a worm gear to a rotary disc that has a
spiral guide. The spiral guide of the rotary disc shifts the
position of one end of a rotatable lever, thus causing the other
end of the rotary lever to actuate a latch mechanism that locks and
unlocks the door.
In this conventional actuator, the spiral guide must be gentle in
its curvature in order to increase the driving force that is
transferred to the rotary lever. When the curvature of the spiral
guide is gentle, however, the magnitude of displacement (stroke
quantum) of the rotary lever relative to the rotation angle of the
rotary disc becomes small. Accordingly, in order to secure a strong
driving force as well as the required stroke quantum, it is
inevitable to design the rotary disc large in diameter, which
contrarily, results in a proportional enlargement of the actuator
as a whole. Besides, the rotary disc is designed to stop after
being positionally shifted; as a result, one end of the rotary
lever is kept in contact with the spiral guide. If, in this state,
an attempt is made to manually operate the door lock latch
mechanism, it demands a strong force because the motor side,
relative to the rotary lever, works as a load.
SUMMARY OF THE INVENTION
Accordingly, the object of the present invention is to provide a
door lock actuator that can sufficiently secure a strong driving
force as well as a necessary stroke quantum for the rotary
lever.
Another object of the present invention is to provide an actuator
for a door lock mechanism which is small in size and with which a
manual door locking operation can be performed under a light
load.
In order to accomplish the objects, the present invention employs
the means as described below which comprises:
a columnar body driven to rotate by a motor that can rotate in
forward and reverse directions in response to control signals
supplied thereto, the columnar body having, on its peripheral
surface, a first spiral stage that provides an upward gradient in a
first direction along the center axis when the columnar body is
rotated in the forward direction, and a second spiral stage that
provides an upward gradient in a second direction along the center
axis when the columnar body is rotated in the reverse direction;
and
a displacement component driven to move, at its one end, in the
first direction by the first spiral stage, when the columnar body
is rotated in the forward direction while driven to move, at the
one end, in the second direction by the second spiral stage, when
the columnar body is rotated in the reverse direction, thus
operating the door lock latch mechanism with the other end.
It is preferable that the columnar body is, after being driven by
the motor to rotate a specified angle, rotated back to its original
position via the rebounding force of a spring. It is also
preferable that the mutual positional relationship of the
displacement component, the first spiral stage, and the second
spiral stage is such that, at least when the columnar body has been
rotated back to the original position, the one end of the
displacement component is not in contact with either the first
spiral stage or the second spiral stage of the columnar body.
It is further preferable that the first spiral stage and the second
spiral stage are formed so that the lead angle of the spiral
portion of each spiral stage gradually changes relative to the
peripheral surface of the columnar body that is in a conical
shape.
In other words, it is desirable to form the columnar body into a
somewhat conical shape by setting the distance, that is between the
center of the columnar body and the point of contact of the end of
the displacement component with the spiral stage (i.e., the radius
of the contact area), so as to become gradually smaller as the lead
angle of the spiral portion of the spiral stage is increased. As a
result, a large stroke quantum can be obtained by the increased
lead angle, and the driving force drop that would be caused by the
increased lead angle is compensated by the thus obtained small
radius of the contact area.
The structure described above brings the effect as follows:
With the forward and reverse rotations of the columnar body, the
contact point of the displacement component with the first spiral
stage and the second spiral stage shifts in the first and second
directions relative to the center axis of the columnar body. In
this case, since the first spiral stage and the second spiral stage
are formed three-dimensionally (in other words in a projected
manner) on the peripheral surface of the columnar body that is in,
for example, a conical shape, the columnar body can be relatively
small in diameter. As a result, a specified driving force and
stroke quantum required for driving the displacement component can
be obtained relatively easily.
In addition, due to the rebounding force of the spring, the
columnar body, after being rotated a specified angle, is rotated to
return to its original position where the one end of the
displacement component is not in contact with either the first
spiral stage or the second spiral stage. As a result, a manual door
locking under a light load is possible.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1(a) is a diagram showing an actuator for a door lock
mechanism as an embodiment of this invention, the actuator being
installed inside the door of an automobile;
FIG. 1(b) is a cross-sectional view showing the internal structure
of the actuator of the present invention;
FIG. 2 is a perspective view showing in detail the structure of the
columnar body and returning spring assembly used in the actuator
for the door lock mechanism provided by the present invention;
FIG. 3(a) is a left side view of the columnar body according to the
present invention;
FIG. 3(b) is a front view thereof;
FIG. 3(c) is a right side view thereof;
FIG. 3(d) is a top view thereof;
FIG. 3(e) is an expanded view thereof; and
FIGS. 4(a) through FIG. 4(e) are diagrams illustrating the
operation of the actuator according to the embodiment of this
invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates a schematic structure of the actuator for a door
lock mechanism according to one embodiment of the present
invention. FIG. 1(a) shows the actuator provided in the door of an
automobile, and FIG. 1(b) shows a cross-section of the
actuator.
In FIG. 1(a), numeral 1 is a door of an automobile; and a latch
mechanism 2, a manual operation button 3, and an actuator 4 are
installed in the door 1 as the components that form the door lock
mechanism. The actuator 4 is remote-controlled by control signals
supplied via a lead wire 5.
In FIG. 1(b), numeral 10 is a case, and a motor 11 that rotates
both ways in response to the control signal supplied via the lead
wire 5 is housed in the case 10. The rotation of the motor 11 is
transferred, through a pinion gear 12 and an intermediate two-stage
gear 13, to a gear 14 of a columnar body 20 that is rotatably
housed in the case 10.
FIG. 2 is a perspective view that shows in detail the structure of
the columnar body 20 and a returning spring assembly 40 of the
actuator for the door lock mechanism of the present invention. The
description of the returning spring assembly 40 will be presented
later.
FIG. 3 illustrates in detail the columnar body 20 according to the
present invention. FIGS. 3(a), 3(b) and 3(c) show the left side,
the front side and the right side of the columnar body,
respectively; FIG. 3(d) is a top view of the columnar body; and
FIG. 3(e) shows the columnar body with the outer surface spread
out.
As shown in FIG. 2 and FIG. 3, the columnar body 20 has a first
spiral stage 21 and a second spiral stage 22. These spiral stages
are formed on the peripheral surface of a conical shaped base body
so that the lead angle of the spiral portions of the spiral stages
gradually changes (as shown in FIG. 3(e), preferably at about 25
degrees). More specifically, the first spiral stage 21 is formed so
as to have an upward-gradient in the first direction A along the
center axis C of the columnar body 20 when the columnar body 20 is
rotated in a forward direction that is shown by arrow M. The second
spiral stage 22 is formed so as to have an upward-gradient in the
second direction B along the center axis of the columnar body 20
when the columnar body is rotated in the reverse direction that is
shown by arrow N.
Returning to FIG. 1, a numeral 30 is a displacement component
formed by connecting two rotary levers 30a and 30b at their base
ends. The connected base ends are axially held by a supporting pin
33 so as to be rotatable. One end 31 of the displacement component
30 is designed so as to come into contact with the first spiral
stage 21 and the second spiral stage 22 of the columnar body
20.
With the arrangement described above, when the columnar body 20 is
rotated in the forward direction as indicated by arrow M, the end
31 of the displacement component 30 is driven to shift its position
in the first direction A, while, when the columnar body 20 is
rotated in the reverse direction as shown by arrow N, the end 31 is
driven in the second direction B. When the end 31 moves like this,
another end 32 of the displacement component 30 operates the latch
mechanism 2 of the door lock.
After being driven by the motor 11 to rotate a specified angle, the
columnar body 20 is stopped via a protruding claw 25 provided on
the columnar body 20 coming into contact with a stopper 15 which
has a buffering member. The thus stopped columnar body 20 is then
rotated back to its original position (which is the position at 0
degrees in FIG. 3(d)) by means of a rebounding force of the spring
assembly 40.
More specifically, as shown in FIG. 2, a protruding portion 23 of
the columnar body 20 is inserted between legs 41 and 42 of the
linear spring member of the spring assembly 40. Also, a cylinder
portion 24 of the columnar body 20 is fitted in the coil portion 43
of the linear spring member of the spring assembly 40. The legs 41
and 42 sandwich both sides of a spring stopper 44 that is an
integral part of the case 10.
With the structure described above, when the columnar body 20 is
driven by the motor 11 to rotate a specified angle, either leg 41
or leg 42 is pushed open. When, in this state, the driving power
for rotation is cut off, the columnar body 20 is rotated back by
the rebounding force of the spring assembly 40 to its original
position.
In the above structure, an adjustment can be made for the relative
dimensions and other interrelations among the displacement
component 30, the first spiral stage 21 and the second spiral stage
22 so that at least when the columnar body 20 has been brought back
to its original position, the end 31 of the displacement component
30 is not in contact with the first spiral stage 21 nor the second
spiral stage 22.
The operation of the actuator of this embodiment will be described
below.
FIG. 4 is an illustration showing the operation of the actuator,
wherein the columnar body 20 is shown stretched out in the
circumferential direction. In the initial stage shown in FIG. 4(a),
the end 31 of the displacement component 30 is positioned near the
foot area of the first spiral stage 21. When, from this initial
stage, the motor 11 operates in the forward direction, the columnar
body 20 is caused to make a forward rotation which is in the
direction of arrow M. This results in that the end 31 of the
displacement component 30 is pushed up by the first spiral stage
21, thus bringing it to the state shown in FIG. 3(b). At this
point, the rotation of the columnar body 20 is stopped by cutting
off the power supply to the motor 11, and the columnar body 20 is
rotated back in the reverse direction via the rebounding force of
the spring assembly 40, thus returning to its original position as
shown in FIG. 3(c). At this time, the end 31 of the displacement
component 30 stays at the pushed-up position as described above and
is not in contact with either the first spiral stage 21 or the
second spiral stage 22. As a result, the displacement component 30
is in the condition to be moved up and down as indicated by the fat
arrow. Therefore, a manual operation of the actuator is available
under a light load.
Next, when, from this state, the motor rotates reversely, the
columnar body 20 is rotated in the reverse direction shown by the
arrow N in FIG. 2(c). This results in that the end 31 of the
displacement component 30 is pushed down by the second spiral stage
22, thereby bringing about the state shown in FIG. 3(d). At this
point, the rotation of the columnar body 20 is stopped by cutting
off the power supply to the motor 11, and the columnar body, as a
result, is rotated back in the forward direction via the rebounding
force of the spring assembly 40, thus returning to its original
position as shown in FIG. 3(c). At this moment, the end 31 of the
displacement component 30 stays at the pushed-down position as
described above and is not in contact with either the first spiral
stage 21 or the second spiral stage 22. As a result, the
displacement component 30 is in the condition to be moved up and
down as shown by the fat arrow. Thus, a manual operation is
available under a light load.
The present invention is not limited to the embodiment described
above. For example, while in the foregoing embodiment a conical
base body is used for the columnar body 20, it is also possible to
use, for example, a cylindrical body that has spiral stage(s)
formed at relatively sharply shifting lead angles. In addition,
undoubtedly, various modifications can be made for the embodiment
without departing from the spirit and the scope of the
invention.
According to the present invention, with the forward and reverse
rotations of the columnar body, the position of the point of
contact of the displacement component with the first spiral stage
and the second spiral stage moves in the first direction and in the
second direction about the center axis of the columnar body. In
this case, because the first spiral stage and the second spiral
stage are formed three-dimensionally relative to the peripheral
surface of the columnar body of, for example, a conical shape, the
columnar body can be relatively small in diameter. As a result, it
is easy to obtain a specific driving force as well as stroke
quantum which are necessary to actuate the displacement component.
Also, since the columnar body, after being driven to rotate a
specified angle by the motor, is rotated back to the original
position where the first spiral stage and the second spiral stage
are not in contact with the end of the displacement component, a
manual operation is available under a light load to lock the door
with use of a manual operation button. Thus, according to the
present invention, the actuator for the door lock mechanism can
secure the strong driving force as well as the necessary stroke
quantum, can be reduced in size, and makes it possible to perform
the manual operation to lock the door under a light load.
* * * * *